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Fjords and mountains in Northern Norway The Arctic Councils Arctic Monitoring and assessment Programme ( AMAP ) recently released a Summary for PolicyMakers Arctic Climate Change Update 2024. It is one of several stock taking exercises on the regional and global states of Earth’s climate. The other reports include the 2024 European State of the Climate (ESOTC) report , NOAAs Assessing the Global Climate in 2024 , Berkeley Earth , and the World Meteorological Organization’s (WMO) stat
This month’s open thread. Note that the Nenana Ice challenge break up date graph has been updated, and the Yukon river ice break up is imminent (or may have already happened!). Please stay focused on climate issues. The post Unforced variations: May 2025 first appeared on RealClimate.
This month’s open thread for climate topics. Please try to stay focused on climate instead of generic (and tedious) political sniping. The post Unforced Variations: Apr 2025 first appeared on RealClimate.
The WMO released its (now) annual s tate of the climate report this week. As well as the (now) standard set of graphs related to increasing greenhouse gas concentrations , rising temperatures , reducing glacier mass, etc., Zeke Hausfather and I wrote up a short synthesis on the contributions to recent temperature anomalies. Readers will recall our previou s discussions on the anomalies in 2023 in particular, and the myriad of ideas that people have published to explain them.
Glaciers are important indicators of climate change. A recent study published in the leading journal Science shows that glaciers in the tropical Andes have now retreated further than at any other time in the entire Holocene – which covers the whole history of human civilisation since the invention of agriculture. These findings are likely to resonate beyond the scientific community, as they strongly support the lawsuit filed by a Peruvian farmer against the energy company RWE, which has re
While there have been some recent set-backs within science and climate research and disturbing news about NOAA , there is also continuing efforts on responding to climate change. During my travels to Mozambique and Ghana, I could sense a real appreciation for knowledge, and an eagerness to learn how to calculate risks connected to climate change. Recent events have shown incredibly high rainfall amounts that have devastated cities and countries , as well as droughts that have exacerbated the ris
Guest commentary by Robert Hart, Kerry Emanuel , & Lance Bosart The National Weather Service (NWS) and its parent agency, the National Oceanic and Atmospheric Administration (NOAA), delivers remarkable value to the taxpayers. This efficiency can be demonstrated by its enormous return on investment. For example, the NWS costs only several dollars per citizen to operate each year, yet results in an estimated 10-100 times larger financial return that includes: improved citizen preparedness, imp
This month’s open thread on climate topics. Despite everything going on, please avoid generic political arguments – there are many other places on line for that. Impacts on climate science or actions from the layoffs in the US federal government are, however, very much on topic. The post Unforced Variations: Mar 2025 first appeared on RealClimate.
Ive been getting a lot of media queries about a new paper on the AMOC , which has just been published. In my view this large media interest is perhaps due to confusing messages conveyed in the title of the paper and in press releases about it by the journal Nature and by the Met Office. Whether intended or not, these give the impression that new model results suggest that the AMOC is more resilient than previously thought.
One more dot on the graphs for our annual model-observations comparisons updates. Given how extraordinary the last two years have been, there are a few highlights to note. First, we have updated the versions of a few of the observational datasets: UAH TLT/TMT are now on version 6.1, and the NOAA NCEI surface temperature data are now version 6. We use the same collations of Hansen81/Hansen88/CMIP3/CMIP5/CMIP6 model output as previously.
There’s been a bit of media whiplash on the issue of AMOC slowing lately – ranging from the AMOC being “on the brink of collapse” to it being “more stable than previously thought” AMOC, of course, refers to the Atlantic Meridional Overturning Circulation, one of the worlds major ocean circulation systems which keeps the northern Atlantic region (including Europe) exceptionally warm for its latitude.
To no-one’s surprise 2024 was the warmest year on record – and by quite a clear margin. Another year, another data point. Unlike the previous year, 2024 was anticipated to be a record breaker even before it began ( I predicted a record – despite the huge anomaly in 2023 – with a 55% probability). It did fall at the higher end of the prediction, so maybe we are seeing the same issues that we saw in 2023 continue into another year.
This month’s open thread on climate topics. Please remember to be substantive, respectful and vaguely on topic. Note that we’ll have an update to the various observational datasets after Jan 10th, and hopefully an update to all the model-observation comparisons the week following (depending on other things not getting in the way). Happy New Year to you all!
Rapid progress in the use of machine learning for weather and climate models is evident almost everywhere, but can we distinguish between real advances and vaporware? First off, let’s define some terms to maximize clarity. Machine Learning (ML) is a broad term to distinguish any kind of statistical fitting of large data sets to complicated functions (various flavors of neural nets etc.), but it’s simpler to think of this as just a kind of large regression.
This is a follow-on post to the previous summary of interesting work related to the temperatures in 2023/2024. I’ll have another post with a quick summary of the AGU session on the topic that we are running on Tuesday Dec 10th, hopefully in the next couple of weeks. 6 Dec 2024: Goessling et al (2024) This is perhaps the most interesting of the papers so far that look holistically at the last couple of years of anomalies.
This month’s open thread on * climate * topics. Obviously, last month’s events lent themselves to broader discussions, but this month (and going forward), we remind you that comments have to be climate-related. Note too that there are plenty of dying websites where you can troll to your heart’s content and post tedious partisan talking points, but here they will be unceremoniously deleted.
It’s 20 years since we started blogging on climate here on RealClimate (December 10, 2004). We wanted to counter disinformation about climate change that was spreading through various campaigns. In those days it was an unusual move that prompted a welcome from Nature. One thing that I didn’t anticipate then was the vast global scale that fake news and conspiracy theories later would attain.
There is a need to make climate science more agile and more responsive, and that means moving (some of it) from research to operations. Readers here will know that the climate science community has had a hard time giving quantitative explanations for what’s happened in climate over the Nature 2023 ?”>last couple of years or even over the last couple of decades.
This month’s open thread on climate change topics. How are we in November already? And why is it still so warm… ? Anyway, please stay on topic and avoid insulting other commenters. The post Unforced variations: Nov 2024 first appeared on RealClimate.
An interesting commentary addressing a rather odd prior commentary makes some very correct points. Back a few months there was a poorly argued and rather confusing commenary by Ulf Büntgen ( Buntgen, 2024 ) that started: I am concerned by climate scientists becoming climate activists, because scholars should not have a priori interests in the outcome of their studies.
The title of this post might seem like a truism, but for about a decade some people have claimed the opposite, and many people have spent much time and effort trying to understand why. Much of that effort was wasted. A decade ago, Nature Geoscience published Cohen et al (2014) , a review paper on potential connections between the Arctic warming and extreme events (which has been cited an impressive 1449 times), which quite sensibly concluded that: …improved process understanding, sustained
This month’s open thread for climate topics. Please stay vaguely on topic and do not abuse other commenters. The post Unforced Variations: Oct 2024 first appeared on RealClimate.
A truly impressive paper was published this week with a new reconstruction of global temperatures over the last ~500 million years. There is something tremendously satisfying about seeing a project start, and then many years later see the results actually emerge and done better than you could have imagined. Especially one as challenging as accurately tracking half a billion years of Earth’s climate.
This month’s open thread on climate topics. Please stay focused, minimize repetitive comments, and maintain a half-way decent level of decorum. Thanks! The post Unforced variations: June 2024 first appeared on RealClimate.
There were a number of media reports today related to Yuan et al. (2024) , for instance, New Scientist , The Guardian etc. However, this is really just the beginning of what is likely to be a bit of a cottage industry in the next few months relating to possible causes/influences on the extreme temperatures seen in 2023. So to help people keep track, we’ll maintain a list here to focus discussions.
This month’s open thread on climate topics. Many eyes will be focused on whether April temperatures will be the 11th month in row of records… Note that we have updated the data and figures from the Nenana Ice Classic and Dawson City river ice break up pools (the nominal 13th and 5th earliest break-ups (or 15th and 4th, w.r.t. to the vernal equinox) in their respective records)).
There has been a lot of commentary about perceived disagreements among climate scientists about whether climate change is, or will soon, accelerate. As with most punditry, there is less here than it might seem. Last year, Jim Hansen and colleagues published a long paper that included a figure suggesting that they expected that global temperature trends from 2011 to increase above the recent linear trends.
This month’s open thread on climate topics. Lots more discussion about 2023 , aerosols, heat content and imbalances to come I expect… Note, comments should be substantive even if you are arguing with who you perceive to be the worst person in the world. Comments that are mainly personal attacks will just get deleted. The post Unforced variations: Apr 2024 first appeared on RealClimate.
Going back a few months, I spent a bit of time pointing out the strategy and nonsense in the various Willie Soon and company’s efforts to blame current warming on solar activity. I specifically pointed out their cultish devotion to a single solar activity reconstruction (Hoyt and Schatten, 1993) (HS93); with an update from Scaffeta (2023) , and their increasingly elaborate efforts to create temperature series that correlate to it.
The month’s open thread on climate topics. More record monthly warmth, but only the second lowest Antarctic sea ice though (growing since 2023!). The post Unforced variations: March 2024 first appeared on RealClimate.
A new paper was published in Science Advances today. Its title says what it is about: “Physics-based early warning signal shows that AMOC is on tipping course.” The study follows one by Danish colleagues which made headlines last July, likewise looking for early warning signals for approaching an AMOC tipping point (we discussed it here ), but using rather different data and methods.
This month’s open thread for climate topics. This month’s climate highlight will likely be the PACE launch at some point between Feb 6th and Feb 8th, that will hopefully provide information on aerosols and ocean color with more detail than ever before. Fingers crossed! A few notes on the blog and commenting. We have an open thread (this one!
A recent sensible-sounding piece by Roy Spencer for the Heritage foundation is full of misrepresentations. Let’s play spot the fallacy. Comparing climate models to observations is usually a great idea, but there are some obvious pitfalls to avoid if you want to be taken seriously. The most obvious one is to neglect the impacts of internal variability – which is not synchronized across the models or with the observations.
Annual updates to the model-observation comparisons for 2023 are now complete. The comparisons encompass surface air temperatures, mid-troposphere temperatures (global and tropical, and ‘corrected’), sea surface temperatures, and stratospheric temperatures. In almost every case, the addition of the 2023 numbers was in line with the long term expectation from the models.
As the climate monitoring groups add an additional dot to their graphs this week, there is some disquiet among people paying attention about just how extraordinary 2023 really was. First, it’s been obvious for months that 2023 would be a record year – in temperatures (at the surface, troposphere and in the ocean), in Antarctic sea ice, in the number of big climate disasters etc.
For the last few years ( since at least 2016 ), I’ve shared predictions for the next annual global mean surface air temperature (GMSAT) anomaly based on the long term trend and the state of ENSO at the start of the year. Generally speaking, this has been quite skillful compared to persistence or just the long term trend alone – the eventual anomaly was consistently within the predicted bounds.
New year, new open thread on climate topics. Note that summaries and updates to include 2023 data will be posted on the surface temperature graphics page and model-observations comparison page over the next couple of weeks as the data becomes available. The post Unforced variations: Jan 2024 first appeared on RealClimate.
This year’s (2023) tropical cyclone season in the North Atlantic and Caribbean witnessed a relatively high number of named tropical cyclones : 20. In spite of the current El Niño, which tends to give lower numbers. But it appears to follow a historical trend for named tropical cyclones with an increasing number over time. The number of North Atlantic/Caribbean named tropical cyclones in and the estimates based on the area with sea surface temperature above 25.6°C (Benestad, 2009).
Well, that year went quickly. This month, there is the COP28 hoopla , the ongoing El Niño and the speculation about the 2023 temperature ranking (which will not be that surprising). An open thread for climate topics… The post Unforced Variations: Dec 2023 first appeared on RealClimate.
It is 33 years now since the IPCC in its first report in 1990 concluded that it is “certain” that greenhouse gas emissions from human activities “will enhance the greenhouse effect, resulting on average in an additional warming of the Earth’s surface.” That has indeed happened as predicted, it has been confirmed by a zillion studies and has been scientific consensus for decades.
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